-LRB- EW.com -RRB- -- Millions of `` Game of Thrones '' fans are feeling sadness , outrage , and , sure , some perverse excitement after watching Sunday 's episode titled `` The Rains of Castamere . '' But for Game of Thrones author George R.R. Martin , such reactions to `` The Red Wedding '' are nothing new . Martin has been receiving exclamatory emails about the disastrous Tully-Frey union for more than a decade , ever since he published his Song of Ice and Fire saga 's third novel , A Storm of Swords . Below , the author reveals why Robb had to die , gives his reaction to upset readers and spills the scene 's horrifying real-life inspiration .

ENTERTAINMENT WEEKLY : How early in the process of writing the book series did you know you were gon na kill off Robb and Catelyn ?

George R.R. Martin : I knew it almost from the beginning . Not the first day , but very soon . I 've said in many interviews that I like my fiction to be unpredictable . I like there to be considerable suspense . I killed Ned in the first book and it shocked a lot of people . I killed Ned because everybody thinks he 's the hero and that , sure , he 's going to get into trouble , but then he 'll somehow get out of it . The next predictable thing is to think his eldest son is going to rise up and avenge his father . And everybody is going to expect that . So immediately -LSB- killing Robb -RSB- became the next thing I had to do .

Since Song of Ice and Fire so often subverts reader expectations and avoids traditional fantasy storytelling structures , should fans have any real hope that this tale will have a happy ending ? As The Boy recently said on Thrones , `` If you think this has a happy ending , you have n't been paying attention . ''

I 've stated numerous times that I anticipate a bittersweet ending .

EW : What sort of reactions have you received from readers over the years about the scene ?

Extreme . Both positive and negative . That was the hardest scene I 've ever had to write . It 's two-thirds of the way through the book , but I skipped over it when I came to it . So the entire book was done and there was still that one chapter left . Then I wrote it . It was like murdering two of your children . I try to make the readers feel they 've lived the events of the book . Just as you grieve if a friend is killed , you should grieve if a fictional character is killed . You should care . If somebody dies and you just go get more popcorn , it 's a superficial experience is n't it ?

EW : Why do you think it has such a powerful reaction ? Robb was n't one of your `` viewpoint characters '' in the books and Catelyn was n't really a beloved personality .

-LSB- Long pause -RSB- That 's an interesting question . I do n't know if I have a good answer . Maybe the way I did it . There 's a certain amount of foreboding leading up to it . It 's a betrayal . It comes out of left field . It 's at a wedding feast . Robb has made his peace and you think the worst is over . Then it comes out of nowhere . There 's also secondary characters killed . Then outside hundreds of Stark people are killed . It 's not just two people .

To me , that Robb and Catelyn are family makes it worse . And Catelyn has suffered so much and lost so many people around her , and she actually thinks she 's lost more than she really has -LRB- since she does n't know for sure that Arya , Bran and Rickon are alive -RRB- . Then this happens .

She also has the moment there to plead . There 's also her murdering the hostage . He 's not a son that Frey particularly values . * So in the end her bluff is empty . And she does . She carries through . There 's a certain power to that too .

EW : I 'm pretty sure I know the answer to this , but : Have you ever regretted the scene ?

Martin : No . Not as a writer . It 's probably the most powerful scene in the books . It cost me some readers , but gained me many more . It 's going to be hard for me to watch it -LSB- on the show -RSB- . It 's going to be a tough night . Because I love these characters too . And in a TV show you get to know the actors . You 're also ending that relationship with an actor that you have affection for . Richard Madden and Michelle Fairley have done an amazing job .

EW : What do you say to readers who are upset about the scene ?

It depends on what they say . What can you say to someone who says they 'll never read your book again ? People read books for different reasons . I respect that . Some read for comfort . And some of my former readers have said their life is hard , their mother is sick , their dog died , and they read fiction to escape . They do n't want to get hit in the mouth with something horrible . And you read that certain kind of fiction where the guy will always get the girl and the good guys win and it reaffirms to you that life is fair . We all want that at times . There 's a certain vicarious release to that . So I 'm not dismissive of people who want that . But that 's not the kind of fiction I write , in most cases . It 's certainly not what Ice and Fire is . It tries to be more realistic about what life is . It has joy , but it also had pain and fear . I think the best fiction captures life in all its light and darkness .

One of my favorite elements of the scene is you introduce this idea of `` salt and bread . '' We accept that as readers â $ '' Okay , in this fantasy world , people do n't harm each other once they eat a host 's bread and salt in their home . Then you break your own rule . It 's like you 're smacking the reader upside the head for being so dense â $ '' `` Of course they 're not going to follow that silly rule ALL the time ! ''

It was stolen from history . Hospitality laws were real in Dark Ages society . A host and guest were not allowed to harm each other even if they were enemies . By violating that law , the phrase is , they `` condemn themselves for all time . ''

EW : What about the Red Wedding itself ? Is that based on history too ?

The Red Wedding is based on a couple real events from Scottish history . One was a case called The Black Dinner . The king of Scotland was fighting the Black Douglas clan . He reached out to make peace . He offered the young Earl of Douglas safe passage . He came to Edinburgh Castle and had a great feast . Then at the end of the feast , -LSB- the king 's men -RSB- started pounding on a single drum . They brought out a covered plate and put it in front of the Earl and revealed it was the head of a black boar â $ '' the symbol of death . And as soon as he saw it , he knew what it meant . They dragged them out and put them to death in the courtyard . The larger instance was the Glencoe Massacre . Clan MacDonald stayed with the Campbell clan overnight and the laws of hospitality supposedly applied . But the Campbells arose and started butchering every MacDonald they could get their hands on . No matter how much I make up , there 's stuff in history that 's just as bad , or worse .

* Changed to one of Frey 's young wives in TV version

See the original story at EW.com .

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George R.R. Martin explains why Robb had to die

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He said reactions have been both positive and negative

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Martin said it was the hardest scene he ever had to write